Demand-based messaging is a communication service that allows users to exchange message data, such as text, over a network or other communications media, in real time. Probably the most common medium for exchange is the Internet, but as wireless phone networks continue to expand, their popularity for text messaging is also expanding. Instant Messaging (IM) is perhaps the most widely known and used embodiment of demand-based messaging. Today, most network and online service providers offer some form of IM service.
IM users typically use a networked computer and IM client software to exchange messages with one another in conversational style. An IM client provides an interface for users to compose, send, receive, and read text messages. Examples of IM clients that are popular today include IBM's SameTime, MSN Messenger, and Yahoo/AOL Instant Messenger. Web-based interfaces are also gaining popularity.
In a graphical display, an IM client usually provides several windows, through which a user can compose and read messages. IM clients generally provide some facility for managing lists of contacts, particularly other IM users. These lists are referred to colloquially as “buddy lists.” See, e.g., U.S. Pat. No. 6,750,881 (issued Jun. 15, 2004). It is common practice to organize such lists into groups of related users, wherein the IM client displays the various groups in a hierarchical tree that can be collapsed and expanded as the user desires.
It is also common, though, for a user to amass rather large buddy lists. The number of groups also tends to expand steadily over time. Conventional buddy list management facilities quickly become inadequate for organizing such large lists. As a result, individual buddy list entries often are duplicated inadvertently in different groups. Thus, there is a need for an improved buddy list management interface that allows an IM user to dynamically identify duplicate entries before adding a new entry.